Biomarkers are molecular indicators of a specific biological property, a biochemical feature or facet that can be used to measure the progress of a disease or the effects of a treatment. For example, serum low-density lipoprotein (LDL) is a biomarker of cholesterol and blood pressure, while the P53 gene is a biomarker for cancer. For chronic diseases and conditions, such as diabetes and allergies, accurate diagnosis is particularly important, especially where the side effects of a treatment are severe.
Diagnostic tests using biomarkers as molecular indicators not only detect the presence or absence of the biomarker, but often must measure the exact concentration of a biomarker to determine whether an abnormal condition exists. Because of the requirement for accuracy, the process of sample collection, preparation, and analysis are often complicated and time consuming. Currently, blood-based assays for biomarker presence or activity are considered to be the “gold standard” for biomarker-type assays.
Despite the desire for accurate results, rapid, point of care analysis of biological samples using biomarkers is becoming increasingly important in the present medical environment due to the need for quick results.